Hiow to replace wall wart on step up with battery

Herman,
Once again, thanks for all the info.

But it does leave me a bit confused. The limits of my electrical understanding must have been reached, so if this seems too elementary, bear with me.

I don't understand how the AC to DC conversion is done externally to the Lukaschek if the output from the WW is marked "24V 250mA, AC," rather than "24V 250mA,DC." The Lukaschek case, itself, is marked "24V, 3 VA" above the input connector -- a further confusing item for me.

Many of the WW's I have for, admittedly less complex, devices are marked DC on the output description. That makes it clear to me that these devices operate internally on DC.

I also e-m'd the distributor of the Phonomena and Benz about the output of the Phonomena, and their reply was that the Benz is AC while the Phonomena was DC.

So how does this all fit together? I understand what you have written about battery choice, etc. It also makes sense to me that the conversion from AC to DC for the Lukaschek would take place outside of the unit itself because of its small size. The output info on the WW and what's printed on the case of the Lukaschek, though.... The case of the Lukaschek is metal, and I assume that it is supposed to operate, at least partially, as a heat sink. It stays warm to the touch

I guess it's clear that the background issue is that I am concerned about frying this in some way, and this leads me to proceed with caution in what I might actually be a rather straightforward process.

So, what am I missing?

Thanks.

You are missing nothing, I was wrong. Sorry. I looked at some websites for info on the Benz and for some reason gathered that the supply to it was DC. I now look and see that it says right on the front of the unit that it is AC 24V 3VA.

The only way you are going to run this off batteries is to go inside the unit, figure out where DC regulators are, and feed DC from the batteries directly to the regulators. I doubt you want to do that.

Herman,
At least, I did manage to learn a good bit from this dialogue. You are right that feeding DC from the batteries directly to the regulators is something tht I don't want to attempt. Seemed like such a good idea, though....